Method and apparatus for intraoperative measurements of anatomical orientation

ABSTRACT

Electronic devices that detect their position and/or orientation with respect to earth&#39;s frame of reference are described. A coupler can removeably maintain the electronic devices in physical proximity of one another. Each electronic device can have a housing and the coupler can be included on the housing and arranged to physically connect the housing of the electronic device to the housing of at least one other electronic device. Alternatively, the coupler can be a packaging that maintains the electronic devices in physical proximity of one another. Each electronic device can be calibrated using the orientation or position information obtained by other electronic devices maintained by the coupler. Further, each electronic device can include a power source that remains inactive until the device is ready for use.

FIELD

The present disclosure generally relates to measuring orientation and/orposition of a patient's anatomy during surgery.

BACKGROUND

Medical practitioners (e.g., surgeons) often need to assess the positionand/or orientation of a patient's anatomy while performing medicalprocedures (e.g., surgery). For example, a surgeon may requireinformation regarding the position and/or orientation of a patient'sbones with respect to the patient or a reference coordinate system inorder to visualize the patient's anatomy and/or determine theposition/orientation in which medical instruments used to assist inperforming the medical procedure should be positioned. Further, medicalpractitioners performing medical procedures in which the patient'sanatomy is being altered (e.g., a traditional pedicle subtractionosteotomy, which can involve removal of a portion of the bone in thevertebra of the patient) may need to assess the amount of change that isbeing made to the patient's anatomy at any given point of time duringthe medical procedure.

Although imaging techniques (e.g., CT-scans, x-rays, etc.) can be usedto plan for a desired anatomical correction to the patient's body(pre-operation) and/or determine whether the desired anatomicalcorrection has been achieved (post-operation), intraoperative imaging todetermine the on-going changes to the patient's anatomy can bedifficult, inconvenient, and result in interruption of the medicalprocedure. For example, when performing an operation to correct ananatomical issue in a patient's spine, intraoperative assessment of thechanges in the patient's anatomy, using traditional imaging techniques,may require the medical practitioner to pause the medical procedure(e.g., step back from the operating table and allow an imaging device tobe brought in) so that an image of the patient's anatomy can beobtained.

Further, most traditional imaging techniques tend to only providesnapshots of the patient's anatomical structure. Although thesesnapshots can illustrate progressive changes to the patient's anatomy ina quantitative manner, they do not provide data of the changes as theyoccur in real-time. Additionally, depending on how the imaging device ispositioned, the obtained image can be a subjective representation of thepatient's anatomy. Therefore, when used intraoperatively, the surgeonperforming the surgery may need to make a subjective assessment of whena desired anatomical orientation has been achieved. This can result insub-optimal patient outcomes and repeat surgeries due to over- orunder-correction with respect to the planned correction.

Exemplary systems and methods for intraoperatively measuring anatomicalorientation using electronic devices are disclosed in U.S. applicationSer. No. 14/471,120 filed on Aug. 28, 2014, which is hereby incorporatedby reference in its entirety. There is a continual need for improvedways of packaging, calibrating, and testing surgical electronic devices,improving the accuracy of such devices, and for making such devices moreuser-friendly.

SUMMARY

Systems and method for measuring the position or orientation of asurgical instrument or patient anatomy using electronic devices aredisclosed herein, as are various ways of packaging, calibrating, andtesting such devices.

Systems and methods according to the embodiments described herein relateto determining at least one of an orientation or a position of a devicewith respect to earth's frame of reference. In one aspect, an apparatuscomprising a plurality of electronic devices and a coupler is described.Each electronic device can detect at least one of an orientation or aposition of the electronic device with respect to earth's frame ofreference. The coupler is configured to removeably maintain theplurality of electronic devices in physical proximity of one another.The coupler maintains the plurality of electronic devices in at leastone of a similar orientation or a similar position.

In another aspect, a system comprising a plurality of electronicdevices, a coupler, and a processor configured to communicate with theplurality of electronic devices is described. Each electronic device candetect at least one of an orientation or a position of the electronicdevice with respect to earth's frame of reference. The coupler isconfigured to removeably maintain the plurality of electronic devices inphysical proximity of one another. The coupler maintains the pluralityof electronic devices in at least one of a similar orientation or asimilar position. The processor can communicate with the plurality ofelectronic devices and can control calibration of each electronic deviceusing orientations or positions detected by other electronic devices.

In yet another aspect, a method for determining at least one of anorientation or position of a medical instrument or an orientation orposition of an anatomical feature on a patient that includes coupling anelectronic device to the medical instrument or the feature of thepatient's anatomy is described. The electronic device can be a deviceselected from among a plurality of electronic devices each configured todetect at least one of an orientation or a position of the electronicdevice with respect to earth's frame of reference. The plurality ofelectronic devices can be removeably coupled to one another in at leastone of a similar orientation or a similar position and in physicalproximity of one another. The described method also includes determiningat least one of the orientation or position of the medical instrument orthe orientation or position of the feature of the patient's anatomybased on the orientation or the position detected by the electronicdevice coupled thereto.

In other examples, any of the aspects above, or any system, method,apparatus, and computer program product method described herein, caninclude one or more of the following features.

The coupler can maintain each electronic device in an orientation inwhich the electronic device is expected to detect the orientation orposition most accurately. Each electronic device can include a housing.The coupler can be included on the housing and can physically connectthe housing of the electronic device to housing of at least one otherelectronic device. The housing can include one or more features forconnecting the electronic device to at least one of a location within anoperating room, a medical instrument in the operating room, a locationon body of a patient, or for aligning the apparatus with an anatomicalfeature of the patient in the operating room. The coupler can connectthe housing of the electronic device to the housing of the at least oneother electronic device using at least one of a mechanical connection ora magnetic connection. The housing can include one or more markingsconfigured to assist a user in aligning the electronic device with thebody of the patient.

The coupler can allow movement of at least one electronic device to adesired projection plane and the processor can use a quaterniongenerated based on the movement of the electronic device to define aprojection plane used for controlling calibration of the electronicdevice. Alternatively or additionally, the coupler can to maintain theplurality of electronic devices in a predetermined similar orientationand the processor can use a fixed quaternion value representing theorientation of the electronic devices to define a projection plane usedfor controlling calibration of each electronic device.

The coupler can include a packaging that maintains the plurality ofelectronic devices in at least one of physical proximity of one anotheror a specific physical orientation with respect to one another. Thepackaging can be at least one of round or human body-shaped. Thepackaging can include one or more markings configured to assist a userin aligning the plurality of electronic device with the body of thepatient. The packaging can include one or more features for maintainingeach electronic device within the packaging. The packaging can include atemperature controller configured to maintain the electronic device at apredetermined temperature. Each electronic device can include aninternal power source. The internal power source can be configured toremain inactive while the electronic device is maintained by thepackaging. The internal power source can be configured to be activatedonce the electronic device is removed from the packaging.

Each electronic device can include an internal power source. Theinternal power source can be configured to remain inactive while theelectronic device is maintained by the coupler. The internal powersource can be configured to be activated once the electronic device isdetached from the coupler. The internal power source can be connected toat least one of a removable pull-tab or a magnetic reed switch andconfigured such that the internal power source remains inactive prior toat least one of removal of the pull-tab or activation of the magneticreed switch and becomes activated upon removal of the pull-tab oractivation of the magnetic reed switch.

Each electronic device can include a cover configured to removeablycover at least a portion of the electronic device. The cover can beconnected to a switch. The switch can activate the internal power sourceupon removal of the cover. The internal power source can be arrangedsuch that it remains inactive prior to removal of the cover.

Each electronic device can include a temperature controller thatmaintains the electronic device at a predetermined temperature. Theelectronic device can further include a communications interface thatreports the detected orientation or position of the electronic device toa computing device that makes use of the detected orientation orposition information.

Each electronic device can include an interface that is arranged totransfer at least one of power from an external power source to theelectronic device or data between the electronic device and an externalprocessor.

Other aspects and advantages of the invention can become apparent fromthe following drawings and description, all of which illustrate theprinciples of the invention, by way of example only.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a block diagram of an example electronic device that can beused with the embodiments disclosed herein.

FIG. 1B illustrates an example electronic device that can be used withthe embodiments disclosed herein.

FIG. 1C illustrates the example electronic device of FIG. 1B as attachedto a surgical instrument.

FIG. 1D illustrates a connector that can be used connect the electronicdevice of FIG. 1B to the surgical instrument shown in FIG. 1C.

FIG. 1E illustrates an example embodiment in which multiple electronicdevices, of the type shown in FIG. 1B, are coupled with one another.

FIG. 1F illustrates an example electronic device in which the electronicdevice includes a housing having a generally round shape.

FIG. 1G illustrates an example embodiment in which multiple electronicdevices, of the type shown in FIG. 1F, are coupled with one another.

FIG. 2A is an example of a packaging that can be used with theelectronic device shown in FIG. 1B.

FIG. 2B is a perspective view of the example packaging shown in FIG. 2A.

FIG. 2C is a top view of the example packaging shown in FIG. 2B.

FIG. 3 is block diagram of an intraoperative measurement system that canbe used with the embodiments disclosed herein.

FIG. 4 is an example flow diagram of procedures for using an electronicdevice in a medical procedure according to the embodiments disclosedherein.

DETAILED DESCRIPTION

Systems and method for measuring the position or orientation of asurgical instrument or patient anatomy using electronic devices aredisclosed herein, as are various ways of packaging, calibrating, andtesting such devices.

FIG. 1A is a block diagram of an example electronic device 100 that canbe used with the embodiments disclosed herein. FIGS. 1B-1C and 1E-1Gdemonstrate other examples of the electronic device 100. FIG. 1Dillustrates an example connector that can be used to couple anelectronic device 100 to a surgical instrument.

Referring to FIG. 1A, the electronic device 100 can include componentssuch as a processor 110, a memory 120, a system interface 130, and acommunications interface 140. The electronic device 100 can also includevarious components configured for obtaining and/or detecting informationregarding the orientation and position of the electronic device 100. Forexample, the electronic device 100 can include an accelerometer 150(e.g., a 9-axis accelerometer for measuring one or more angles of theelectronic device 100 with respect to a reference point such as theearth), a gyroscope 160 or a gyroscopic sensor, and a magnetometer 170.The electronic device 100 can be implemented in digital electroniccircuitry or computer hardware.

The components included in the electronic device 100 can be arrangedsuch that they communicate with one another to detect, obtain, process,communicate, and/or store information regarding the position and/ororientation of the electronic device 100 and one or more surgicaldevices 190 (shown in FIG. 1C) to which the electronic device 100 can beattached. The components shown in FIG. 1A, and any other component thatcan be used with the electronic device 100, can be included withinhousing 192 of the electronic device 100 and/or be positioned externalto the housing 192 of the electronic device 100.

The processor 110 can be any processor known in the art and include amicrocontroller, a microcomputer, a programmable logic controller (PLC),a field-programmable gate array (FPGA), an application specificintegrated circuit (ASIC), integrated circuits generally referred to inthe art as a computer, and/or other programmable circuits.

The processor 110 can be coupled to the memory 120, which can include arandom access memory (RAM), a read-only memory (ROM), a flash memory, anon-transitory computer readable storage medium, and so forth. Thememory 120 can store instructions for execution by the processor 110 toimplement the systems disclosed herein or to execute the methodsdisclosed herein. Additionally or alternatively, the memory 120 canstore information regarding the position and/or orientation of theelectronic device 100, calculated by the processor 110 or obtained byother components of the electronic device 100, and/or received from anexternal device through the communications interface 140. The memory 120can also store calibration information for the components included inthe electronic device 100.

The processor 110 can be in communication with a system interface 130and a communications interface 140 (e.g., Bluetooth). The systeminterface 130 can, for example, be a Universal Serial Bus (USB)connector. The system interface 130 can be connected to an externalpower source 180 such as an electric charger (e.g., power adapter)and/or a power terminal. The USB connector 130 can be arranged such thatit can connect to one or more peripherals (e.g., USB cable) that connectthe electronic device 100 to the power supply 180. Alternatively oradditionally, the electronic device 100 can include an internal powersupply 182 (e.g., battery, for example a lithium ion battery) thatprovides the electronic device 100 with electronic power.

The communications interface 140 can be configured to receive andtransmit information to/from any of the processor 110, the memory 120,or other internal or external components and devices (e.g., anothersurgical electronic module, a base station, etc). The communicationsinterface 140 can be wireless (e.g., near-field communication (NFC),Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, etc.) or wired (e.g., USB orEthernet). In the case of NFC, for example, electronic device 100 caninclude a radio transceiver (not shown) configured to communicate with aradio transceiver of another device (e.g., a second module, using one ormore standards, such as ISO/IEC 14443, FeliCa, ISO/IEC 18092, and thosedefined by the NFC Forum). The communication interface 140 can beselected to provide the desired communication range. Bluetooth (e.g.,class 2 Bluetooth having a range of 5-10 meters) can be used for thecommunication interface to allow the electronic device 100 to remainsomewhat distant from the device with which it is communicating (e.g.,the second module and/or a base station, while at the same time limitingthe communication range such that other mobile devices unlikely to beused in the surgery are not needlessly involved).

As noted, the processor 110 can be communicatively coupled with theaccelerometer 150, gyroscope 160, and magnetometer 170 and arranged suchthat it can obtain information regarding the position and/or orientationof the electronic device 100 from these components and/or performvarious calculations based on the positional/orientation informationdetected by these components. Specifically, the gyroscope 160 can beused to measure the current orientation of the electronic device 100 inthree dimensions in an inertial frame of reference. The accelerometer150 can also be used along with the gyroscope to measure acceleration,inclination, and movements of the electronic device in three dimensions.The magnetometer 170 (or a magnetic sensor) can further be used todetermine the positioning of the electronic device 100 relative to themagnetic north (i.e., the magnetic heading of the electronic device100). The processor 110 can combine and process the information obtainedfrom the accelerometer 150, gyroscope 160, and the magnetometer 170 todetermine the absolute position and/or orientation of the electronicdevice 100 in three dimensions. The processor 110 can also calculate arelative position and/or orientation of the electronic device 100 withrespect to an external reference point based on the absolute positionand/or orientation of the electronic device 100.

The processor 110 can be configured to detect an absolute positionand/or orientation of the module in the spherical coordinate system withthe earth as reference. Additionally or alternatively, the processor 110can be configured to detect the positional information at intervalsthroughout a surgical procedure, for example every second, everymillisecond, every microsecond, etc., such that thepositional/orientation information is effectively detected continuouslyand in real-time. The positional/orientation information can be detectedregularly, intermittently, or at non-regular intervals. Thepositional/orientation information can be conveyed to the user (e.g.,surgeon), stored in the memory 120, conveyed to the processor 110 forprocessing, and/or communicated to one or more external devices via thecommunications interface 140 for processing or storage. In someembodiments, the electronic device 100 can include an electronic displaymounted in or on a housing of the electronic device. Alternatively, orin addition, the electronic display can be disposed remotely from theelectronic device, for example in a user device as discussed furtherbelow.

The processor 110 can be configured to determine both an orientation anda position (e.g., a distance of the electronic device 100 from somereference point) by being configured to switch between an orientationdetection mode in which the processor 110 only detects the orientationand a full detection mode in which the processor 110 detects both theorientation and the position. The electronic device 100 can beconfigured to switch between the orientation detection mode and the fulldetection mode at the request of the user, for example via actuation ofan input device (not shown) connected to the electronic device 100,and/or based on an identity of the surgical device to which theelectronic device 100 is attached.

The positional information detected and/or calculated by the electronicdevice 100 can include one or more angles of the electronic device 100with respect to the earth (absolute angle), one or more angles of themodule with respect to a some other reference point (relative angle),distances between the electronic device 100 and one or more externalreference points, changes in any of these values, a rate of changes inany of these values, and/or higher order derivatives of any of thesevalues. The electronic device 100 can be configured to detect and/orcalculate the positional information in a variety of units andcoordinate systems. To provide relevant anatomical measurements duringsurgery, the electronic device 100 can be configured to translatepositions and/or orientations detected in a conventional sphericalcoordinate system into positions and/or orientations along conventionalsagittal, axial, and coronal planes.

The electronic device 100 can further include a housing 192. The housing192 can assume any size and shape. For example, as shown in FIG. 1B,FIG. 1C, and FIG. 1E, the housing 192 be generally box-shaped (e.g.,rectangular or square). Additionally or alternatively, the electronicdevice 100 can assume any other shape and/or be amorphous. For example,FIG. 1F and FIG. 1G illustrate examples in which the housing 192 of theelectronic device assumes a generally round shape.

The housing 192 of the electronic device 100 can be arranged tofacilitate the coupling of two or more electronic devices 100 to oneanother. For example, as shown in FIGS. 1F and 1G, the electronic device100 can include one or more slots 104 and/or corresponding tabs 102 thatare configured to facilitate coupling of the electronic devices 100 toone another. The tab 102 can be a snap tab and configured such that itallows the electronic devices 100 to snap into one another. FIG. 1Gillustrates an example in which three electronic devices 100 (labeled as1, 2, and 3) have been coupled with one another.

Further, as illustrated in FIG. 1C, the housing 192 can be configuredsuch that it facilitates the coupling of the electronic device 100 withone or more surgical devices 190. It will be appreciated that theelectronic device 100 can be formed integrally with a surgical device,or can be selectively coupled or attached thereto. Exemplary surgicaldevices include surgical instruments (e.g., drivers, rongeurs, forceps,distractors, retractors, and the like) and surgical implants (e.g., boneanchors, bone plates, fixation or stabilization rods and other hardware,joint replacement implants, intervertebral cages, and the like). Theelectronic device 100 can also be configured to attach directly to ananatomy of a patient. The electronic device 100 can be attached toscrews used in performing spinal surgery (e.g., pedicle screws) and/orto a driver shaft that attaches to the pedicle screws. Further, whenperforming surgical operations that alter the shape or size of a bone(e.g., osteotomy), one or more sensors can be positioned on each side ofthe area to which the alteration is being applied (e.g., each side ofthe osteotomy). Alternatively or additionally, additional sensors can bepositioned on various portions of the patient's body (e.g., at one orboth ends of a patient's spinal column) to measure the global positionor orientation to which the alteration is being applied. Additionalelectronic devices 100 can be utilized. For example, additionalelectronic devices 100 can be attached to various parts of the patient'sbody, the surgical bed, or at any position remote from the surgicalsite. Additional electronic devices 100 can also be mounted on any ofthe surgical tools used in performing the surgery.

The electronic device 100 can be attached to the surgical device 190using any technique known in the art, for example, using a connector101, similar to that illustrated in FIG. 1D. The housing 192 can includeone or more features that can both facilitate the coupling of theelectronic device 100 with one or more surgical instruments 190 andallow for coupling of two or more electronic devices 100 with oneanother. FIG. 1E illustrates another example in which multipleelectronic devices 100 are connected to one another. The housings of theelectronic devices can include complementary shapes such that they nestwith each other. Alternatively or in addition to the features includedon the housing 192, two or more electronic devices 100 can be coupled toone another using any type of attachment known in the art, for examplemechanical and/or magnetic attachments.

Further, as described in U.S. application Ser. No. 14/471,120 filed onAug. 28, 2014, the entire teachings of which are incorporated herein byreference, the electronic device 100 can continually detect changes in aposition and/or orientation of the surgical device 190 during surgeryand communicate the detected changes to a user (e.g., medicalpractitioners performing the surgery). The surgical device 110 can beattached to a portion of a patient's anatomy and/or be used tomanipulate the patient's anatomy. The electronic device 100 can detectthe changes in the position and/or orientation of the surgical device190 by quantitatively measuring changes in the position and/ororientation of the surgical instrument 190, or of an anatomicalstructure to which the electronic device 100 or the surgical instrument190 are connected, during surgery.

In embodiments that incorporate more than one electronic device 100, theelectronic devices 100 can continually detect changes in their positionsand/or orientations relative to one another. These detected changes canbe interpreted by the electronic devices 100 to determine the changes inrelative positions and/or orientations of the surgical device(s) 190 towhich the electronic devices 100 are attached. Additionally oralternatively, at least one of the electronic devices 100 can help toestablish a reference 3D location in the operating room, particularlywhere the at least one electronic device is stationary.

As noted, the electronic device 100 and its components can beimplemented in hardware, for example on chip. Depending on the type ofhardware used to implement the electronic device 100, the accuracy ofthe positional information obtained from the electronic device 100 maydepend on the position/orientation at which the electronic device 100and its components are positioned. Accordingly, embodiments disclosedherein orient the electronic device 100 and its components within itshousing 192 such that the orientation expected to yield optimal (e.g.,more accurate) positioning information is aligned with the plane ofinterest for the patient. Some orientation-sensing hardware, forexample, is more accurate in one plane or dimension that in others.Accordingly, such hardware or the printed circuit board to which it ismounted can be oriented within the housing 192 such that, when thehousing is aligned with the patient according to the system instructionsor external markings on the housing, the more-accurate measurementdimension of the hardware is aligned with the dimension of primaryinterest for the surgical procedure being performed.

The housing 192 can assume various shape and forms. For example, thehousing 192 can be box-shaped, rounded, amorphous, or be in the shape ofthe human body or body part. Alternatively or additionally, the housing192 can be in the form of a sticker or tape that can be affixed to orcoupled with a person's (patient's) body. Generally, the housing 192 canassume any shape or form that facilitates the usage of the electronicdevice 100 in the application or the procedure in which the electronicdevice 100 is being used. For example, an electronic device 100 thatassumes the form of a sticker or adhesive tape can be adhered orotherwise attached to the patient. Once attached or placed on thepatient body, the electronic device 100 can be used to determine theposition and orientation of the location to which the electronic device100 is adhered and/or serve as a reference point. For example, theelectronic device 100 can be affixed to a relatively stationary portionof the patient's body (e.g., close to a relatively stationary part ofthe patient's bony anatomy) and serve as a reference point to connectthe positional measurements to other measurements, for example thoseobtained using x-ray or other imaging techniques. The housing (e.g.,sticker) 192 can have properties that allow the electronic device 100 tobe visible when using imaging techniques to obtain three dimensional(3D) images of the surgical site. For example, the electronic devices100 can be visible in X-ray Fluoroscopy, thereby allowing the locationand orientation of the electronic devices 100 to be visible in the 3Dimages obtained using this technique. The sticker can be in the form ofa map that corresponds with the packaging in which a plurality ofelectronic devices 100 are disposed. In this manner, the sticker canserve as a diagrammatic guide to assist the user in placing eachelectronic device included in the packaging in the correct position fora given procedure.

The electronic device 100 can be packaged in a packaging that isseparate from the housing 192 of the electronic device 100. FIG. 2A isan example of a human body-shaped packaging 210 that can be used withthe embodiments disclosed herein. In the embodiment shown in FIG. 2A,multiple electronic devices 100 are packaged into a single packaging210. The packaging 210 can assume any shape (e.g., generally box-shaped,amorphous, etc.) or size. For example, as shown in FIG. 2, the packaging210 can be human-shaped. The human-shaped packaging 210 can facilitatethe usage of the electronic device 100 since the surgeon or medicalpractitioner can simply align the packaging 210 with the patient's body.For example, the packaging 210 can be arranged that such an axis (e.g.,the caudal axis) of the packaging is brought into alignment with acorresponding axis (e.g., the caudal axis) of the patient once a portionof the packaging (e.g., the head of the human-shaped packaging) isaligned with a corresponding portion of the patient's body (e.g., thehead of the patient). Such arrangement can assist with registering theaxes of the electronic device 100 with corresponding axes in thepatient's body, thereby facilitating the alignment of the electronicdevice 100 with the patient's body. The controlling software in 330 canbe programmed with the packaging configuration such that the relativealignment of all the sensors is known. For example, the operating tablecan be assumed to be parallel to the ground, the package can have a flatbottom, and the sensors can know their position with respect to gravitysuch that once the package axis is aligned with the cranial/caudal axisof the patient, the system can match the coordinate systems of thesensors to the coordinate system of the patient and allow for a singlestep calibration method. The operating table can be manipulated suchthat the head can be higher or lower than the feet, but not axiallyrotated, such that a rotational axis reference can be established withthe flat bottom package resting on the patient at the beginning of theprocedure.

Each packaging 210 can contain one or more electronic devices 100. Forexample, in the embodiment shown in FIG. 2A, the human-shaped packaging210 is shown as including three electronic devices 100. Each electronicdevice 100 included in the packaging can utilize data obtained from theother electronic devices 100 in the package to calibrate itself.Calibration of the electronic devices 100 can be done in various ways.For example, the calibration of the electronic device can generallyinvolve using acceleration and magnetic data obtained from theaccelerometer 150 and magnetometer 170 to determine informationregarding the orientation of the electronic device 100 and using thechanges in the orientation information to calibrate the gyroscope 160.

Further, the embodiments disclosed herein can orient each electronicdevice 100 within the packaging 210 in a position and/or orientationexpected to yield optimal (e.g., more accurate) positioning information.The electronic devices 100 can be packaged in an orientation thatprovides the highest accuracy in calibration-related use. Specifically,as noted, depending on the type of hardware used to implement theelectronic device 100, each electronic device 100 can be more accuratein one direction than in other directions. Therefore, embodimentsdisclosed herein achieve more accurate calibration results by orientingthe electronic devices 100 within the packaging 210 such that the axesof the electronic devices 100 that are expected to yield the moreaccurate results are aligned with the plane of interest for the patient.

The packaging 210 can have one or more markings (not shown) that can beused to create alignment with patient. The markings can allow alignmentto a patient in the sagittal or transverse plane. Additionally oralternatively, the packaging 210 can include one or more notches 220(e.g., jigs) that maintain and/or force the electronic devices 100 intoalignment with one another and also with the packaging 210. Thealignment notches 220 can also simultaneously maintain the electronicdevices 100 in alignment during calibration.

Although shown in FIG. 2A as including more than one electronic device,the packaging 210 can include a single electronic device. FIG. 2Billustrates a perspective view of an example human-shaped packaging 210that contains a single electronic device 100. FIG. 2C illustrates a topview of the human-shaped packaging shown in FIG. 2B that includes asingle electronic device. As shown in FIG. 2A, the packaging 210 caninclude one or more notches 220 (e.g., jigs) that maintain and/or forcethe electronic device 100 into alignment with the packaging 210.

The packaging 210 can be positioned on any location on the patient'sbody or placed/mounted at any location within the area in which themedical procedure is being performed. For example, the packaging 210 canbe temporarily mounted to the patient's bed or patient's bedrail toassist in alignment of the patient with the packaging 210, and theelectronic device(s) 100 disposed therein, and also to ensure that thepackaging 210 and its electronic device(s) 100 are not shifted duringthe medical procedure.

The packaging 210 can include various features for positioning/attachingthe packaging 210 to the patient's body or a location within thesurgical site. For example, the packaging can include an adhesivefeature that can be used to attach the packaging to a desired location(e.g., adhesive sticker, double-sided tape, etc.) or a clamp that can beused to attach the packaging to a location within the surgical site(e.g., patient's bed or bedrail).

The packaging 210 can include one or more features for indicatingsuccessful calibration of the electronic device(s) 100. Alternatively oradditionally, the features 230 for indicating successful calibration canbe included on the housing of the electronic device 100 and/or be acomponent included in the electronic device 100. The indicator means 230can include light, tone/sound, and/or vibration features that light up,generate a tone, and/or vibrate upon successful calibration of eachelectronic device 100 and/or once all of the devices included inpackaging 210 have been successfully calibrated.

The packaging 210 can be arranged such that it allows for verificationof successful calibration of the electronic device(s) 100 and fordetermining whether any errors in the calibration process have occurred.For example, the packaging 210 can be in the form of a circular blockthat can hold one or more electronic devices 100 and can rotate theelectronic devices 100 about a common axis. This allows for verificationof accuracy of the gyroscope 160 included in each of the electronicdevices 100. Specifically, since the electronic devices 100 included inthe packaging 210 share a common axis, if a gyroscope 160 included in anelectronic device 100 included in a package 210 provides a reading thatis different from the other electronic devices 100 in that package 201,that electronic device can be marked/labeled as one that requirescalibration and/or as an unstable electronic device. Similarly, themeasurements obtained from the accelerometer 150 of each electronicdevice 100 can be compared against the reading obtained from the rest ofthe electronic devices 100 and an electronic device 100 whoseaccelerometer 150 detects an angular acceleration that is different fromthe angular acceleration obtained by the other electronic devices can bemarked as unstable and/or in need of calibration. The marking/labelingof the electronic device as one that requires calibration and/or as anunstable electronic device can be done using an application program thatruns on a computer within the operating room (described later withrespect to FIG. 3). Alternatively, or in addition, the system can applya software correction to the discrepant electronic device.

Although the calibration and verification procedures disclosed above aredescribed with respect to one or more electronic devices that are heldin a common packaging 210, these procedures can be carried out withoutrequiring the sensors to be contained in the packaging 210.Specifically, as shown in FIG. 1E and described above, the electronicdevices 100 can be coupled to one another using mechanical or magneticattachments. The coupled electronic devices 100 can be arranged suchthat they allow for verification of successful calibration of eachelectronic device(s) 100 and for determining whether any errors in thecalibration process have occurred. Further, the electronic devices canbe coupled such that they share a common axis so that each electronicdevice 100 can use information obtained from the other electronicdevices to calibrate. Specifically, since the coupled electronic devices100 share a common axis, if a gyroscope 160 included in an electronicdevice 100 provides a reading that is different from the otherelectronic devices 100 to which that device is coupled, that electronicdevice can be marked/labeled as one that requires calibration and/or asan unstable electronic device. Similarly, the measurements obtained fromthe accelerometer 150 of each electronic device 100 can be comparedagainst the reading obtained from the rest of the electronic devices 100and an electronic device 100 whose accelerometer 150 detects an angularacceleration that is different from the angular acceleration obtained bythe other electronic devices can be marked as unstable and/or in need ofcalibration.

Once calibrated, the electronic devices 100 can be removed from thepackaging 210 and/or uncoupled from one another (e.g., coupledconfigurations shown in FIGS. 1E and 1G) and used within the operatingsite. Once removed, if an electronic device 100 requires furthercalibration, it can simply be attached back to other electronic devices100 and/or placed back within the housing 210.

The physical connection between the electronic devices 100 in a devicepack (e.g., coupled configurations shown in FIGS. 1E and 1G) and/or theproximity achieved by maintaining the electronic devices 100 within asingle housing can allow the electronic devices 100 to communicate withone another so that they can calibrate (or re-calibrate). Specifically,the electronic devices 100 can include at least one of a magnetic,physical, or electronic (e.g., Bluetooth, Near Field Communication(NFC)) switch that triggers the resetting of the electronic device 100once the electronic device 100 is connected to other electronic devicesand/or placed in the packaging 210. The resetting or “zeroing” of theelectronic device 100 allows a user to selectively set an initialrelative position and/or orientation of the electronic device 100 tozero. Subsequent changes in the relative positions and/or orientationsof the electronic device 100 can be measured and displayed to the userso that the user knows when a desired change in position and/ororientation of the modules has been reached.

Referring back to FIG. 1A, the internal power source 182 included in theelectronic device 100 can be a deferred action power source, such as adeferred action battery. Deferred action batteries allow activation ofthe electronic device at the time of use, thereby preventing the batteryof the device from draining itself prior to being used. The deferredaction power source can employ any of a variety of deferred actionfeatures. For example, the deferred action power source can be a powersource having a removable barrier that is configured to isolate variousportions of a battery cell (e.g., the electrodes and the electrolyte)from one another. The barrier can be arranged such that as long as thebarrier is in place, the battery 182 remains inactive. However, onceremoved, the portions of the battery 182 that were previously isolatedcome in contact with one another, thereby activating the battery 182.The barrier can be a fragile barrier that can be broken or removed toactivate the battery 182. For example, the barrier can be formed, atleast in part, of plastic, paper, or similar fragile materials.

The barrier can include a portion 185 that extends out of the electronicdevice 100 so that the barrier can be manipulated and/or removed as afunction of manipulation of the portion that extends out of theelectronic device 100. For example, the barrier can include a pull-tab185 that extends out of the electronic device 100 and arranged such thatthe removal and/or manipulation of the pull-tab 185 (e.g., tearing,pulling, shaking, etc.) results in manipulation of the barrier andactivation of the battery 182. The pull-tab can be attached to thepackaging of the electronic device 100 such that the pull-tab isautomatically actuated to connect the power supply when the electronicdevice is removed from the packaging.

Alternatively or additionally, the electronic device 100 can have aninternal power source 182 that is remotely activated. For example, theelectronic device 100 can include a battery 182 that can be activated byshaking the electronic device 182.

In some implementations, the electronic device 100 can include aninternal power source 182 that remains inactive as long as theelectronic device 100 remains in the packaging 210 and/or as long as theelectronic device 100 remains attached to other electronic devices. Theinternal power source 182 can be arranged such that it is activated uponremoval of the electronic device 100 from the packaging 210 and/or uponuncoupling the electronic device 100 from being attached to otherelectronic devices.

As noted, the electronic device can include means for coupling (e.g.,tabs 102 and slots 104 shown in FIGS. 1F-1G) the electronic device toother electronic devices (e.g., magnetic connections, mechanicalconnections) and/or be maintained in a packaging using holding means,such as jigs 220. The internal power source 182 can be arranged suchthat the power source 182 remains inactive as long as the coupling means(e.g., 102, 104) remain engaged to connect the electronic device 100 toother electronic devices 100 and/or as long as the holding means (e.g.,jigs) 220 are being used to maintain the electronic device within thepackaging.

In some implementations, alternatively or in addition to a deferredaction power source, the electronic device can include one or morefeatures for separating or disconnecting the power source 182 from theelectronic device to ensure that the power source 182 is only active, inuse, or connected while the electronic device is in use. For example,the electronic device 100 can include a feature, such as a pull-tab 186,that separates the power source 182 (e.g., battery) from the electronicdevice 100 (or the circuit included in the electronic device). Thefeature can be arranged such that removal and/or manipulation of thepull-tab 186 (e.g., tearing, pulling, shaking, etc.) can result increating and/or establishing a connection between the power source 182and the circuit of the electronic device 100, thereby providingelectronic power to the electronic device 100.

In some implementations, the electronic device can include a powersource that remains disconnected from the electronic circuit of theelectronic device as long as the electronic device remains in thepackaging 210 and/or as long as the electronic device remains attachedto other electronic devices. The power source 182 can be arranged suchthat it establishes a connection with the electronic circuit of theelectronic device 100 to provide electronic power to the electronicdevice upon removal of the electronic device 100 from the packaging 210and/or upon uncoupling the electronic device from being attached toother electronic devices.

As noted, the electronic device can include features for coupling (e.g.,tabs 102 and slots 104 shown in FIGS. 1F-1G) the electronic device toother electronic devices (magnetic connections, mechanical connections)and/or be maintained in a packaging using holding means 220, such asjigs. The internal power source 182 can be arranged such that the powersource 182 remains disconnected from the electronic device (i.e.,disconnected from the electronic circuit including the componentsincluded in the electronic device 100) for as long as the coupling means102, 104 remain engaged to connect the electronic device to otherelectronic devices and/or as long as the holding means 220 (e.g., jigs)are being used to maintain the electronic device within the packaging210. The power source 182 can be arranged such that once removed fromthe packaging and/or disengaged, the power source 182 can establish aconnection to the electronic circuit of the electronic device to providethe electronic device with electronic power.

In some implementations, the power source 182 can be controlled by aswitch 183 that can be used to activate or deactivate the power source182 so that the power source 182 remains inactive and unconsumed as longas the switch 183 remains inactive. Alternatively or additionally, theswitch 183 can be used to connect or disconnect the power source 182from the electronic device. The switch 183 can be a reed switch, such asa magnetic reed switch. The magnetic reed switch 183 can be arrangedsuch that it remains inactive while the device 100 is attached to otherelectronic devices 100 and/or as long as the device 100 remains in thepackaging 215 and becomes activated once the device 100 is removed fromthe packaging 215 and/or is uncoupled from other electronic devices 100.The magnetic reed switch 183 can be a magnetically actuated reed switch183 and include a magnet (not shown) that is arranged to transition thereed switch between closed and open positions. For example, the magneticreed switch can include a magnet that maintains the switch in the openposition as long as the electronic device 100 is attached to otherelectronic devices 100 and/or as long as the device 100 remains in thepackaging 215. The magnet can be further arranged such that the removalof the electronic device 100 from the packaging 215 and/or uncoupling ofthe electronic device 100 from other electronic devices 100 can causethe magnet to close the switch 183 and connect the power source 182 ofthe electronic device 100 to the other components of its electroniccircuit. The switch 183 can be any type of switch known in the art. Themagnet can further be any type magnet, including magnets in which amagnetic field can be induced. The switch 183 and/or magnet can beremotely controllable such that the switch and/or magnet can be remotelyactivated (e.g., closing of the switch) or deactivated. For example, theswitch 183 or the magnet can be controllable using a wireless Bluetoothconnection.

In some embodiments, the electronic device can include reed switchdisposed between an internal power source of the electronic device andthe electronic device's logic board or other circuitry. The electronicdevice can be sterilized and/or stored prior to use in a box or otherpackaging that includes a magnet aligned with the reed switch tomaintain the reed switch in an open position. Upon removal of theelectronic device from the packaging, the magnet disposed in thepackaging is moved out of proximity with the reed switch, causing thereed switch to transition to a closed position and thereby supply powerfrom the internal power source to the logic circuitry of the electronicdevice. Accordingly, the battery can be “remotely” coupled to the othercircuitry of the electronic device, avoiding the need for a switch thatrequires a housing penetration. This can be desirable to help withsterilization of the device and maintain the sterility of the device.

In some embodiments, the electronic device 100 can include a cover 193.The cover 193 can be a part of the housing or separate from the housing.The cover 193 can be arranged such that it covers at least a portion ofthe housing. The electronic device 100 can be arranged such it isactivated upon the removal of the cover 193. For example, the cover 193can be arranged such that its removal triggers the activation of theswitch 183 and/or the power source 182, as described above. The cover193 may be mechanically or magnetically coupled to a switch 183 and orpower source 182. In some embodiments, the electronic device 100 caninclude a spring-loaded plunger that is held down by the coverand/packaging. The packaging and/or the cover 183 can be arranged suchthat removal of the electronic device from the packaging and/oropening/removal of the cover causes the plunger to spring out andactivate the internal power source 182.

The electronic device 100 can be configured to automatically begin acalibration routine when power is first supplied thereto.

FIG. 3 is a block diagram of an intraoperative measurement system 300that can be used with the embodiments disclosed herein. Theintraoperative measurement system 300 can include one or more userdevices 320 that connect with the electronic device 100 or one or moreelectronic devices 100 to control, manage, and use the device 100 toobtain information regarding the patient's anatomical orientation and/orposition.

As shown in FIG. 3, a user (not shown, such as a medical practitioner ora surgeon) can use the user device 320 to connect with the electronicdevice 100. The user device 320 can be any type of a communicationsdevice that is capable of establishing direct or indirect communicationlink 305 with other devices (e.g., electronic device 100). For example,the user device 320 can include Bluetooth capabilities that enable theuser device 320 to communicate with other Bluetooth compatible devices(e.g., electronic device 100). Alternatively or additionally, thecommunications device 320 can connect with other devices through acommunication network (not shown, e.g., the Internet, a private network(e.g., local area network (LAN)). The communications device 320 canconnect to other devices wirelessly or through a wired link.

Examples of the user devices 320 that can be used with the embodimentsdescribed herein include, but are not limited to, wireless phones, smartphones, desktop computers, workstations, tablet computers, laptopcomputers, handheld computers, personal digital assistants, etc. Eachuser device 320 can have a screen that may be used to receive anddisplay information. The screen can be a touch screen. Each user device320 can further include a monitoring application 330 that can be usedfor controlling the electronic device 100 and/or receiving (e.g.,orientation and/position information) or transmitting (e.g., calibrationinformation, initialization or resetting information) to/from theelectronic device 100. The monitoring application 330 can be used toanalyze the information received from the electronic device 100 and/orpresent the user with information that could be used for intraoperativesurgical planning (e.g., estimated post-operative outcome). For example,the monitoring application 330 can employ a predictive model to providean estimate of the amount of correction that can be achieved from agiven surgical adjustment.

The information retrieval application 330 can be presented to the userof the user device 320 using a user interface (not shown). Additionallyor alternatively, the information retrieval application 230 can bepresented to the user using application software that provides aninteractive medium for receiving input from the user. The informationretrieval application 330 can be a web-based platform. Alternatively oradditionally, the user device 320 can access the information retrievalapplication 330 through an interactive medium provided by theapplication software or using the web-based interface.

FIG. 4 is an example flow diagram of procedures for using an electronicdevice 100 in a medical procedure according to the embodiments disclosedherein. The procedures shown in FIG. 4 need not occur in any specificorder and can occur in any order.

As noted the electronic device 100 can be powered using an externalpower source 180 (e.g., a USB connection-based power source) and/or aninternal power source 182. Further, as noted, the electronic device 100can remain inactive and only activated once it is ready for use. Forexample, the electronic device can be provided with power 410 byactivating a switch 183 and/or manipulating a tab 185, 186 to connectthe electronic components included in the electronic device 100 with anelectronic power source 180, 182.

Further, as noted above, the electronic device 100 can be included in ahousing 192 or a packaging 210 that facilitates the alignment of theelectronic device 100 with the patient's body. Specifically, sincedepending on the type of hardware used to implement the electronicdevice 100, the accuracy of the positional information obtained from theelectronic device 100 may depend on the position/orientation at whichthe electronic device 100 and its components are positioned, embodimentsdisclosed herein orient the electronic device 100 and its componentswithin its housing 192 such that the orientation expected to yieldoptimal positioning information is aligned with the plane of interestfor the patient. The housing 192 or packaging 210 can be marked orshaped in a manner intended to assist with aligning the electronicdevice 100 with the patient's body. For example, the housing 192 and/orpackaging 210 can be box-shaped, rounded, amorphous, or be in the shapeof the human body and/or in the form of a sticker or tape that can beaffixed to or coupled with a person's (patient's) body. The surgeon canuse the shape or the markers to align the packaging 210 or housing 192with the patient's body. The packaging 210 and/or the housing 192 canalso have markings that can be used to define alignment to the patientin sagittal or transverse plane and/or force the electronic devices 100into alignment.

The electronic device 100 (or devices, if multiple devices are used) canbe calibrated 430. The electronic device 100 can utilize data obtainedfrom the other electronic devices 100 in the package to calibrateitself. Alternatively or additionally, the electronic device 100 canreceive the required calibration data from the user through the userdevice 320. During the calibration procedure for defining the projectionplane, the electronic devices can be placed aligned to each other andthe electronic devices can be calibrated to each other. Further, oneelectronic device can be rotated about the normal to a desiredprojection plane and a quaternion generated can be entered into thecalibration algorithm to define the projection plane. If the electronicdevices are aligned to each other and aligned in a known orientation tothe desired projection plane for the first step, the physical rotationcan be skipped and a fixed quaternion value can be placed into thecalibration algorithm representing the rotation, removing the need forthe physical step to be performed.

As noted, the electronic devices 100 can stay attached to each otherthrough mechanical or magnetic attachment, thereby forcing a certainsequence of use and calibration and fixing their orientation forcalibration. The electronic devices can be attached to each other viatheir packaging 210 and/or by being physically attached throughconnections, such as mechanical or magnetic connections.

Further, separating each electronic device 100 from other devices in thecluster (electronic devices in a packaging or a group of connectedelectronic devices) can trigger that electronic device to turn on. Thesequence in which the electronic devices are removed from the clustercan automatically inform the monitoring application 330 as to the use ofeach electronic device (e.g., electronic device #1 is being attached toa certain tool, electronic devices #2 is being attached to a sacrum,etc.). If the user determines that a device 100 needs to re-calibrated,at any time during use, the electronic device 100 can simply beconnected back into the cluster 455 to prompt a recalibration workflowin the monitoring application 330. Reconnecting the electronic devicescauses the electronic devices to be placed back in a same plane ofreference to assist with calibration relative to each other. Theelectronic devices can be configured such that once connected they canrecalibrate, using a magnetic, physical, or electronic (e.g.,Bluetooth/NFC near field communication) switch that triggers a reset inthe electronic devices and causes them to recalibrate with respect toeach other once they are physically connected to each other. Further,the electronic devices can be configured such that all connectedelectronic devices in a cluster reset every time a new one is added tothe cluster to ensure that all are calibrated to each other properly.

The electronic devices can further be checked for errors before they areused in the medical procedure. For example, an error check can beperformed on the electronic devices contained in a cluster by rotatingthe electronic devices in the cluster around the same axis and checkingthe accuracy of the electronic devices against each other. For example,a circular block that holds all the electronic devices and rotates themabout a common axis can be used to check the accuracy of each of thegyroscopes included in each electronic device against other gyroscopes.If one electronic device appears to produce different results, thatdevice can be recalibrated, marked as unusable, or have a softwarecorrection applied thereto. The accelerometers or other components ofthe electronic devices can also be verified during the error check toensure that they all produce similar measurements when rotated tosimilar angular accelerations.

A warm up time sequence can also be applied to the electronic devicebased on the operating room temperature and/or the preferred operatingtemperature. The warm up sequence can be initialized, monitored, orcontrolled by the monitoring application 330 of the user device 320. Thestartup sequence can be arranged such that it delays the sensingfunctions of the electronic device 100 and/or returns an error codeuntil a predetermined warm up time has passed. The predetermined timecan be any amount of time that may be required for the electronic device100 to achieve its suitable operating temperature. This predeterminedamount of time can be set by the user and/or through the use of themonitoring application 330.

The monitoring application 330 can also be arranged to monitor theinternal temperature of the electronic device 100, the cluster of theelectronic devices 100, the packaging 210, and/or the ambienttemperature and make any required arrangements for delaying the use ofthe electronic device 100 and/or generating an error code until theelectronic device 100 has reached its proper operating temperature.

Further, the packaging 210 and/or the electronic devices 100 can have awarmer 240 (shown in FIG. 2A) that is arranged to maintain theelectronic devices 100 at a desired/optimal working temperature. Thewarmer 240 can be a stand-alone unit in the packaging 210 and/or a partof the circuitry included in the electronic device and/or its housing.The warmer 210 can be connected to the monitoring application 330 suchthat it can be initialized, controlled, and/or monitored by themonitoring application 330. Alternatively, the heat needed to bring theelectronic device to its desired operating temperature can be suppliedby the components included in the electronic device 100 and/or a heatingelement or power source (e.g, battery) disposed in the packaging 210 orin the housing 190. Alternatively or additionally, the electronic device100 can include the required components (e.g., a Peltier device) forcooling the electronic device, its housing 192, or packaging 210 toensure that the temperature of the electronic device 100 is maintainedat a point so that the most optimal (accurate) measurements can beobtained.

The calibration, initialization, error check, and/or startup proceduresdescribed herein can be initialized and/or controlled by the monitoringapplication 330 of the user device 320.

Once initialized, the electronic device(s) 100 can be positioned in theoperating room for use in obtaining measurements 440. As noted, thesequence in which the electronic devices are removed from thecluster/packaging can automatically inform the monitoring application330 as to the use of each electronic device. Alternatively oradditionally, the user can use the monitoring application to record,monitor, and/or control the positions at which the electronic devices100 are disposed.

The electronic devices 100 can be used in obtaining measurements duringthe operation 450 and these measurements can be used in planning themedical procedure at hand 460. New and updated measurements can beobtained 465 as the electronic devices are moved during the medicalprocedure.

It will further be appreciated by a person skilled in the art that thedevices and methods described herein can be particularly useful forrobotic assisted surgery. For example, one or more surgical electronicmodules as described herein can transmit positional information to arobotic manipulator, which can manipulate the one or more modules untilthey have reached a desired final position that has been input to themanipulator.

While the systems and methods disclosed herein are generally describedin the context of spinal surgical procedures on a human patient, it willbe appreciated that they can be readily used in other types of surgery,on non-human patients, or in fields unrelated to surgery.

Although the invention has been described by reference to specificembodiments, it should be understood that numerous changes may be madewithin the spirit and scope of the inventive concepts described.Accordingly, it is intended that the invention not be limited to thedescribed embodiments, but that it have the full scope defined by thelanguage of the following claims.

In the present disclosure, like-numbered components of the embodimentsgenerally have similar features and/or purposes. Further, to the extentthat linear or circular dimensions are used in the description of thedisclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan easily be determined for any geometric shape. Sizes and shapes ofthe systems and devices, and the components thereof, can depend at leaston the size and shape of the components with which the systems anddevices are being used, the anatomy of the patient, and the methods andprocedures in which the systems and devices will be used. The figuresprovided herein are not necessarily to scale. It will be understood thatthe devices and methods specifically described herein and illustrated inthe accompanying drawings are non-limiting example embodiments. Thefeatures illustrated or described in connection with one exampleembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present disclosure.

The invention claimed is:
 1. An apparatus comprising: a plurality ofelectronic devices, each electronic device including an internal powersource and being configured to detect at least one of an orientation ora position of the electronic device with respect to earth's frame ofreference in a plurality of dimensions; and a coupler configured toremoveably maintain the plurality of electronic devices in physicalproximity of one another, the coupler maintaining the plurality ofelectronic devices in at least one of a similar orientation or a similarposition; wherein the internal power source of the electronic device isconfigured to be deactivated when at least a portion of the coupler isin proximity to the electronic device.
 2. The apparatus of claim 1,wherein the coupler is configured to maintain each electronic device inan orientation in which the electronic device is expected to detect theorientation or position most accurately.
 3. The apparatus of claim 1,wherein each electronic device includes a housing, the coupler beingincluded on the housing and configured to physically connect the housingof the electronic device to housing of at least one other electronicdevice.
 4. The apparatus of claim 3, wherein the housing includes one ormore features for connecting the electronic device to at least one of alocation within an operating room, a medical instrument in the operatingroom, a location on body of a patient, or for aligning the apparatuswith an anatomical feature of the patient in the operating room.
 5. Theapparatus of claim 3, wherein the coupler is configured to connect thehousing of the electronic device to the housing of the at least oneother electronic device using at least one of a mechanical connection ora magnetic connection.
 6. The apparatus of claim 3, wherein the housingincludes one or more markings configured to assist a user in aligningthe electronic device with the body of the patient.
 7. The apparatus ofclaim 1, wherein the coupler comprises a packaging, the packaging beingconfigured to maintain the plurality of electronic devices in at leastone of physical proximity of one another or a specific physicalorientation with respect to one another.
 8. The apparatus of claim 7,wherein the packaging is at least one of round or human body-shaped. 9.The apparatus of claim 7, wherein the packaging includes one or moremarkings configured to assist a user in aligning the plurality ofelectronic devices with the body of the patient.
 10. The apparatus ofclaim 7, wherein the packaging includes one or more features formaintaining each electronic device within the packaging.
 11. Theapparatus of claim 7, wherein the packaging includes a temperaturecontroller configured to maintain the electronic device at apredetermined temperature.
 12. The apparatus of claim 7, wherein theinternal power source is configured to be activated once the electronicdevice is removed from the packaging.
 13. The apparatus of claim 1,wherein the internal power source is configured to be activated once theelectronic device is detached from the coupler.
 14. The apparatus ofclaim 1, wherein each electronic device includes at least one of aremovable pull-tab or a magnetic reed switch that is any of mechanicallyand magnetically coupled to at least a portion of the coupler such thatthe internal power source remains inactive prior to at least one ofremoval of the pull-tab or activation of the magnetic reed switch andbecomes activated upon at least one of removal of the pull-tab oractivation of the magnetic reed switch.
 15. The apparatus of claim 1,wherein each electronic device includes a cover configured to removeablycover at least a portion of the electronic device, the cover beingconnected to the coupler and a switch configured to activate theinternal power source.
 16. The apparatus of claim 1, wherein eachelectronic device includes a temperature controller configured tomaintain the electronic device at a predetermined temperature.
 17. Theapparatus of claim 1, wherein each electronic device includes acommunications interface, the communications interface being configuredto report the detected orientation or position of the electronic deviceto a computing device that makes use of the detected orientation orposition information.
 18. The apparatus of claim 1, wherein eachelectronic device includes an interface arranged to transfer at leastone of power from an external power source to the electronic device ordata between the electronic device and an external processor.
 19. Asystem comprising: a plurality of electronic devices, each electronicdevice including an internal power source and being configured to detectat least one of an orientation or a position of the electronic devicewith respect to earth's frame of reference in a plurality of dimensions;a coupler configured to removeably maintain the plurality of electronicdevices in physical proximity of one another, the coupler maintainingthe plurality of electronic devices in at least one of a similarorientation or a similar position; and a processor configured tocommunicate with the plurality of electronic devices; and anon-transitory computer readable storage medium configured tocommunicate with the processor and containing instructions that, whenexecuted by the processor, cause the processor to control calibration ofeach electronic device using orientations or positions detected by otherelectronic devices; wherein the internal power source of the electronicdevice is configured to be deactivated when at least a portion of thecoupler is in proximity to the electronic device.
 20. The system ofclaim 19, wherein the coupler is arranged to allow movement of at leastone electronic device to a desired projection plane and the processor isconfigured to use a quaternion generated based on the movement of theelectronic device to define a projection plane used for controllingcalibration of the electronic device.
 21. The system of claim 19,wherein the coupler is arranged to maintain the plurality of electronicdevices in a predetermined similar orientation and the processor isconfigured to use a fixed quaternion value representing the orientationof the electronic devices to define a projection plane used forcontrolling calibration of each electronic device.
 22. The system ofclaim 19, wherein the electronic device includes a housing, the couplerbeing included on the housing and configured to physically connect thehousing of the electronic device to housing of at least one otherelectronic device.
 23. The system of claim 22, wherein the housingincludes one or more features for connecting the electronic device to atleast one of a location within an operating room, a medical instrumentin the operating room, or a location on body of a patient in theoperating room.
 24. The system of claim 22, wherein the coupler isconfigured to connect the housing of the electronic device to thehousing of the at least one other electronic device using at least oneof a mechanical connection or a magnetic connection.
 25. The system ofclaim 19, wherein the coupler comprises a packaging, the packaging beingconfigured to maintain the plurality of electronic devices in at leastone of physical proximity of one another or a specific orientation withrespect to one another.
 26. The system of claim 25, wherein thepackaging is at least one of round or human body-shaped.
 27. The systemof claim 25, wherein the packaging includes a temperature controllerconfigured to maintain the electronic device at a predeterminedtemperature.
 28. The system of claim 25, wherein the internal powersource is configured to be activated once the electronic device isremoved from the packaging.
 29. The system of claim 19, wherein theinternal power source is configured to be activated once the electronicdevice is detached from the coupler.
 30. The system of claim 19, whereinthe electronic device includes an interface arranged to transfer atleast one of power from an external power source to the electronicdevice or data between the electronic device and an external processor.